Sewing machine looper mechanism



Nov. 27, 1945.

E. MUECKE SEWING MACHINE LOOPER MECHANISM Filed Aug. 1, 1944 3 Sheets-Sheet 1 Kl If; lllwillllyillllllllIllllll I lllll rll lllwl t IIJIIL. L ll l EH J L f,

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SEWING MACHINE LOOPER MECHANISM Filed Aug. 1, 1944 3 Sheets-Sheet 3 V 41 49 e5 QMW Patented Nov. 27, 1945 SEWING MACHINE LOOPER MECHANISM Edward Muecke, Linden, N. J., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application August 1, 1944, Serial No. 547,547

13 Claims.

This invention relates to looper mechanisms for sewing machines and more particularly to looper mechanisms for sewing machines of the twothread chain-stitch type.

The present invention has for its object to provide a simplified form of actuating mechanism fora looper movable in the path of a flattened or long-radius arc, in order to insure seizure by the looper of the needle-thread loops of several needles when spaced apart.

With the above'and other objects in view, as will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings'of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the drawings,

Fig; 1 is a'front side elevation, partly in section, of 'a two-needle double thread chain-stitch sewing-machine embodying the present invention.

Fig. 2 is an enlarged top plan, partly in section, of the sewing machine bed with the clothplate removed.

Fig, 3 is a horizontal section taken longitudinally of the telescopically arranged looper supporting members.

Fig. 4 is an enlarged front end elevation, partly in section, of the sewing looper mechanism.

Fig. 5 is an enlarged vertical section taken substantially on the line 5-5 of Fig. 1.

Fig. 6 is a fragmentary view, in side elevation and partly in section, of the rocking yoke connections for imparting endwise movements to the looper, and

Fig: 7 is an enlarged vertical section taken substantiallyon'the line'1--1,'Fig. 1, and showing the forked arm of the looper-carrier supporting member-as embracing'an accentric'on the "bedshaft for 'imparting'sidewise movements to the looper.

The invention has been embodied in a doublethread chain stitch sewing machine having the usual bed I and bracket-arm 2 with overhanging head 3. J ournaled in the bed I is a rotary actuating shaft 4 with a belt-pulley 5 secured upon its. free end. The actuating shaft 4 is also provided with spaced crank-arms 6 connected by a crank-pin 1 embraced by the lower end of a pitman 8. The upper end of the pitman 8 is pivotally connected bya'pin 9 to a crank-arm I D fixed upon a rock-shaft I l journaled in the bracket-arm 2. One end of the rock-shaft II is pro vided with a crank-arm l2 fitted with a crankpin l3 having a link connection l4 with a'pin 15 of a block l6 clamped upon the needle-barf! which carries at its lower end a pluralityof spaced needles l8.

The sewing machine is provided with a threadlaying mechanism comprising a thread-carrying implement l9 and a spreader 20, all as shown and described in my prior Patent No. 2,350,965, of June 6, 1944, for depositing, in advance of the needles, a covering thread upon the upper face of the work.

Suitably journaled for endwise movement in the sewing machine head 3 is the presser-bar 2! carrying at its lower end the usual presser-foot 22 yieldingly urged into work-engaging position by the flat spring 23.

The feeding mechanism embodied in this machine is of the usual four-motion type comprising the feed-dog 24 secured upon the feed-bar 25 by the fastening screw 26. The feed-bar receives its rising and falling movements from an eccentric 21 mounted upon the rotary or actuating shaft 4. The rear end of the feed-bar is'mounted upon a rocker 28 suitably journaled upon a short shaft (not shown) mounted upon the bed I in the rear of the rotary shaft 4. 'Journaled upon a bearing stud 29 entering the upper part of the feed-rocker 28, is one end of a pitman 30,

ing shaft 4 and journaled intermediate its endsin a suitable bearing block l rising from the bed I. Secured by a clamp-screw 31in the lower end of the looper-carrier 34 is a transverse pivot-pin 38 entering bearing-apertures in the depending head-portion 39 of the looper-carrier supportingv member 36. It will be observed thatthe pivotal axis of the looper-carrier, aiforded by the pivotpin 38, extends crosswise of and is disposed below the rocking axis of the looper-carrier supporting member 36 which is itself disposed a substantial distance below the actuating shaft 4. Consequently, the looper 32 has a long radius of endwise vibratory movement and moves in a flattened arc to facilitate seizure of the needlethread loops of several needles when spaced apart. In order to impart the sidewise movements to the looper, there is secured, by a clamp-screw 40, upon the inner reduced end of the oscillatory looper supporting member 36, the split lower portion of an upstanding forked arm 4| fitted with bearing blocks 42 embracing an eccentric 43 secured upon the rotary actuating shaft 4.

In order to impart the endwise or loop-seizing and shedding movements to the looper 32, the looper-carrier 34, intermediate its ends, has a sliding pivotal connection with a reciprocatory looper-carrier supporting member or bar 44. This bar is slotted at one end to receive the looper-carrier 34 and is telescopically disposed within and coaxially with the outer looper-carrier supporting member 36. The looper-carrier supporting members 36 and 44 hav their common longitudinal axis disposed in substantially the vertical plane containing the aXis of the actuating shaft 4. The sliding pivotal connection between the looper-carrier 34 and the inner loopercarrier supporting member or bar 44 is disposed within the enlarged head of the outer looper-carrier supporting member 36 and comprises a pivotpin 45 which i substantially parallel to the pivotpin 38 and is journaled in alined apertures in the slotted head of the reciprocatory carrier-supporting member 44. The pivot-pin 45 is embraced by a slide-block 46 fitted to move in a longitudinal guide-slot 41 formed in the looper-support 34 in order that the looper-support may swing freely about its pivot-pin 38 in the endwise movements of the looper. The looper-carrier 34 is thus constrained to oscillate with the outer carriersupporting member 36, and swings about an axis transverse to the looper-carrier supports 36 and 44. The other end of the looper-carrier supporting member or bar 44 is iournaled in a bushed bearing 48 in the bed I.

In order to impart endwise movements to the inner looper-carrier supporting member or bar 44, there is loosely fitted thereon, between'spaced collars 49 retained in position upon the bar 44 by clamp-screws 50, the block having alined trunnion-pin 52 embraced by slide-blocks 53 fitted in the forked depending arms 54 of the plural armed rocker 55. The rocker 55 is journaled upon alined pins 56'retained by screws 51 in the upstanding bearing-lugs 58 secured to the sewing machine bed I by the screws 59. The other and generally horizontally disposed arms 60 of the rocker 55, are also fitted with alined trunnionpins 6| retained therein by screw 62. These trunnion-pins 6| enter alined bearing bosses 63 of a strap 64 embracing an eccentric 65, secured by the screw 66, on the actuating shaft 4. The eccentric 65 is provided with a circumferential groove 61 to afford clearance for the proximate ends of the pins 6| during the rotation of the eccentric 65.

It will thus be readily understood that endwise or loop-seizing and shedding movements are imparted to the looper 32 from the inner reciprocatory looper-carrier supporting member 44 and that said member 44 receives endwise movements through the plural armed rocker 55 actuated by the strap 64 embracing the eccentric 65 on the rotary shaft 4. It will also be understood that sidewise movements are imparted to the looper 32 through the outer or oscillatory looper-carrier supporting member 36 which receives its oscillatory movements through the forked arm 4| embracing the eccentric 43 on the actuating shaft 4.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine looper mechanism, in combination, a rotary actuating-shaft, a loopercarrier, a looper mounted thereon, telescopically arranged looper-carrier supporting members, and operative connections between said actuatingshaft and said members for imparting endwise and sidewise movements to said looper.

2. In a sewing machine looper mechanism, in combination, a rotary actuating-shaft, a loopercarrier, a looper mounted thereon, telescopically arranged looper-carrier supporting members disposed below said shaft, and operative connections between said shaft and said members for imparting endwise and sidewise movements to said looper.

3. In a sewing machine looper mechanism, in combination, a rotary actuating shaft, a loopercarrier, a looper mounted thereon, telescopically arranged looper-carrier supporting members, a rocker, an eccentric carried by said shaft for actuating said rocker, operative connections between said rocker and one of said members for imparting endwise movements to said looper, and operative connections between said shaft and the other of said members for imparting sidewise movements to said looper.

' 4. In a sewing machine, the combination with a needle and means for reciprocating the same, of a looper, a looper-carrier, telescopically arranged looper-carrier supporting members, a rocker, operative connections between said rocker and one of said members for imparting endwise movements to said looper, a rock-arm carried by the other of said members for imparting sidewise movements to the looper, and means for actuatcentric for imparting sidewise movement to said looper.

6. In a sewing machine, the combination with a needle and means for reciprocating the same, of a looper, a carrier thereof, telescopically arranged looper-carrier supporting members, a pluralarmed rocker, alined trunnion-pins carried by a pair of arms of said rocker, an actuating eccentric provided with a circumferential clearance groove for said trunnion-pins, a strap embracing said eccentric having alined apertures entered by said trunnion-pins, connections between another'pair of arms of said rocker and one of said telescopically arranged members for imparting endwise movements to said looper, and means including said other telescopically arranged member for imparting sidewise movements to said looper.

7. In a sewing machine looper mechanism, in combination, a rotary actuating shaft, a first looper-supporting member disposed below and parallel to said actuating shaft, a looper-carrier pivotally connected to one end of said loopersupporting member, a looper mounted upon said carrier, a connection between-the other end of said looper-supporting member and said actuating shaft for impartin endwise movements to said looper, a second looper-supporting member arranged coaxially with said first looper-supporting member and embracing said pivotal connection between said looper-carrier and said first looper-supporting member, and a connection between said actuating shaft and said second looper-supporting member for imparting sidewise movements to said looper.

8. In a sewing machine, a rotary actuating shaft, telescopically arranged supporting members having their longitudinal axes in a plane containing the axis of rotation of said shaft, a looper-carrier pivotally connected to each bfsaid supporting members, a looper carried by said looper-carrier, means for endwise reciprocating one of said supporting members for imparting endwise movements to said looper, and means for rocking the other of said supporting members for imparting sidewise movements to said looper.

9. In a sewing machine, a rotary actuating shaft, coaxially arranged looper-carrier supporting members having their common axis in a vertical plane containing the axis of rotation of said shaft, a looper-carrier pivotally connected to each of said supporting members, a looper carried by said looper-carrier, means for endwise reciprocating one of said supporting members for imparting endwise movements to said looper, and means for rocking the other of said supporting members for imparting sidewise movements to said looper.

10. In a sewing machine looper mechanism, in combination, telescopically arranged supporting members, a looper-carrier pivotally connected to each of said supporting members, a looper mounted upon said carrier, and means for actuating said supporting members for imparting endwise and sidewise movements to said looper.

11. Looper mechanism for sewing machines comprising, an oscillatory looper-supporting member, -a looper-carrier pivotally supported by and constrained to oscillate with said looper-supporting member, a looper secured upon said looper-carrier, a bar journaled in said looper-supporting member for endwise reciprocatory movements, a pivotal connection between said bar and said looper-carrier constraining said bar to oscillate with said looper-supporting member, means for reciprocating said bar for imparting endwise movements to said looper, and means for oscillating said looper-supporting member for imparting sidewise movements to said looper.

12. In a sewing machine, a rotary actuating shaft, a looper-carrier, a looper mounted thereon, a looper-carrier supporting member slotted at one end, said looper-carrier being pivotally disposed in the slot of said supporting member, a second looper carrier supporting member slotted at one end to embrace said looper-carrier and providing a second pivotal connection with said looper-carrier, operative connections between said first mentioned looper-carrier supporting member and said actuating shaft for imparting endwise movements to said looper, and operative connections between said second looper-carrier supporting member and said actuating shaft for imparting sidewise movements to said looper.

13. Looper mechanism for sewing machines comprising an oscillatory looper-supporting member, a looper-carrier pivotally supported by said member for swinging movement about an axis transverse to the axis of oscillation of said member, a looper secured upon said looper-carrier, a bar journaled in said looper supporting member for endwise reciprocatory movements, a pivotal connection between said bar and said looper-carrier providing a pivot axis substantially parallel .with the pivot axis connection between said looper-carrier and said supporting member, means for reciprocating said bar for imparting endwise movements to said looper, and means for oscillating said looper-supporting member for imparting sidewise movements to said looper.

EDWARD MUECKE. 

